Safety starting device.



R. HOFFMAN.

SAFETY STARTING DEVICE. APPLICATION FILED APR- 10, l9l6.

Patented July 11, 1916.

UNITED STATES PATENT OFFICE.

RUDOLPH HOFFMAN, or KANKAKEE, ILLINOIS, ASSIGNOR T0 SEARS, ROEBUCK AND COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF NEW YORK.

SAFETY STARTING DEVICE.

To all whom it may concern:

Be it known that I, RUDOLPH HOFFMAN, a citizen of the United States, residing at Kankakee, in the county of Kankakee and State of Illinois, have invented certain new and useful Improvements in Safety Starting Devices, of which thefollowing is a specification.

The object of\ this invention is to provide improved means for insuring that both hands ofthe operator of a punch press, stamping press or similar machine shall be out of the danger zone during the descent of the ram. 1

In the accompanying drawings, Figure 1 is a front elevation of a punch press provided with a safety device embodying the features of my invention. Fig. 2 is a fragmental side elevation of the machine with certain parts in section. Fig. 3 is a plan Section on an enlarged scale, taken in the plane of dotted line33 of Fig. 1. Fig. 4

is a fragmental front elevation. 1 1

The present invention is adapted for application to punch presses, stamping presses and similar. machines of any standard or preferred construction. Such machines are usually arranged so that the clutch is thrown out automatically upon the completion of one revolution of the main shaft. When the clutch is thrown in, the ram descends, then rises and stops. The clutch is herein shown as arranged to be thrown in by means of a bar 1 connected at its upper end to the clutch mechanism and guided at its lower end in a guide 2. Fixed to the bar 1 is a back-plate 3. On the back-plate is a stud '4. The means for drawing the bar 1' downward to throw in the clutch comprises devices arranged to bear against the stud 4. These devices comprise two bell crank levers'5'connected to the back-plate 3 for piv-' otal and downward movement. The levers 5 are arranged opposite to each other, as shown in the drawings, and lie between the back-plate 3 and a front-plate 6, said plates being rigidly secured together. Each lever consists of a downwaidly-extending arm 7 and a horizontal arm 8. Near the angle of the bell-crank ,is a vertically-elongated opening 9 through which extends a stud or pin 10'.

Coiled springs 11 connected to the levers 5 and to the back-plate 3 normally hold the levers in such position that the lower end Specification of Letters Patent.

' walls of the openings 9 are in contact'with the pins 10 and the lower arms of the levers are separated from each other and lie in contact with stop-pins 12. The levers 5 are arranged'to be pivotally moved so that the lower arms 7 lie in contact with each other directly above the stud as shown in Fig. 4. The means for thus swinging the levers 5 comprises two hand-levers 13 piv- 'oted at 14 (Fig. 3) to a support 15 fixed to the machine frame. Each hand-lever is connected with the horizontal arm 8 of one of the levers 5 by means of a link 16. 17 are stops to limit the downward movement of the hand-levers, as will appear hereinafter. Located in the horizontal plane of the handlevers and between said levers is'fixed a bar 18. i v Y To throw in the clutch, the operator grasps both hand-levers 13'and simultaneously depresses said levers. The depression of the hand-levers first results in bringing the arms 7 of the levers 5 together above the stud 4 as indicated in Fig. 4. The continuing depression of the hand-levers causes the arms 7 to bear against the stud 4 and thereby draw the back-plate 3 and bar 1 downward, thus throwing in the clutch. If the operator should endeavor to throw in the clutch by using only one hand-lever 13, the arm 7 of the lever 5 connected to said hand-lever would swing from its stop-pin 12 over to the opposite side of the stud 4, and the hand-lever would come into contact with its stop 17 before the back-plate 3 and the bar 1 were moved downwardly. It will be seen that in order to produce a tlownward movement of the bar 1, the bellcrank levers 5 must be simultaneously swung into contact with each other, so as to prevent either of the arms 7 from "swinging past the stud 4.

Then both hand-levers 13 are simultaneously denressed', .the stops l7do not come into action. the clutch-operating devices controlled by the bar 1 serving to limit downward 'movement of the hand levers.

The stationary bar 18 located between the hand-levers 1B prevents the operator from simultaneously depressing both hand-levers by laying his forearm across them.

I claim as-my invention:

' 1. A machine having a starting member, two relatively-movable elements carried by said member, each of said elements being ar- Patented July 11, 1916.. Application filed April 10, 1916. Serial No. 90,073.

ranged to limit movement of the other, a stud on the starting member arranged to be simultaneously engaged by said elements when their movement is thus limited, two hand-levers each connected to one of said elements, and a stationary member located between the hand-levers to prevent simultaneous depression of both hand-levers with one arm.

2. A machine having a starting member, two bell-crank levers each having an elongated opening therein, pins extending through said elongated openings and securing the bell-crank levers to the starting member, a stop-pin on the starting member for each bell-cranlr lever, spring means tending to hold the bell-crank levers in contact with the stop-pins, a stud on the starting member located between the stop-pins, and means for swinging .the bell-crank levers against the action of the spring means and into engagement with said stud.

3. A machine having a starting member, a bell-crank lever having an elongated opening therein, a pin extending through said elongated opening and securing the bellcrank lever to the starting member, a stoppin on the starting member for the bellcrank lever, spring means tending to hold the bell-crank lever in contact with the 'stoppin, a stud on the starting member, means for swinging the bell-crank lever against the action of the spring means, and manuallyope able means for limiting the swinging movement of the lever when the lever is in alinement with the stud.

4. A. machine having a starting member, two bell-crank levers movably supported opposite each other, a stoppin for each bellcrank lever, springs tending to move the bell-crank levers into contact with their stoppins, a stud on the starting member located between the stop-pins, and means for swinging the bell-crank levers into contact with each other and againstthe stud.

5. A machine having a starting member, two bell-crank levers movably supported by said member, a stop-pin for each bell-crank lever, springs tending to hold the bellcrank levers in contact with their stop-pins, a stud on the starting member located between the stop-pins, and m ans for swinging the bell-crank levers toward each other and into engagement with the stud.

6. A machine having a starting member, a bell-crank lever pivoted on said starting member, a stop-pin on the starting member for the bell-cranlr lever, a spring tending to hold'the bell-crank lever against the stoppin, a stud on the starting member arranged to be engaged by one arm of the lever, means engaging the other arm for swinging the bell-c ank lever, said lever being adapted to swing to the side of the stud opposite to the stop-pin, and means to limit such swinging movement.

7. A machine having a starting member, two relatively mo able elements carried by said member, each of said elements being arranged to limit movement of the other, a stud on the starting member arranged to be simultaneously engaged by said elements when their movement is thus limited, and two hand-levers each connected to one of said elements.

8. A machine having a starting bar, two relatively-movable elements supported by said bar, said elements being arranged to swing into contact with each other, whereby each limits movement of the other, a.stud on the starting bar arranged to be simultaneously engaged by said elements when their movement is thus limited, and two handlevers each linked to one of said elements for swinging said elements toward each other.

9. A. machine having a starting member, a bell-crank lever pivoted on said starting member, a stud on the starting member, means for swinging the bell-crank lever, and manually-operable means to limit such swinging movement when one arm of said lever is in alinement with the stud.

10. A machine having a starting member, two bell-crank levers movably supported upon said member, a stud on the starting member, and means for swinging the bellcrank levers into engagement with the stud.

11. A machine having a starting member, a stud on the starting member, two relatively-movable elements supported for-lost motion with relation to the starting member, and means for simultaneously pressing both elements against the stud.

12. A machine having a starting member, two bell-crank levers movably supported upon said member, a stud on the starting member, and means for swinging the bellc'rank' levers into contact with each other and into engagement with the stud.

13. A machine having a starting member, tw 0 relatively-movable elements supported for lost motion with relation to the starting member, each of said elements being arranged to limit movement of the other, a stud on the starting member, and means for moving said elements into engagement with the stud.

In testimony whereof, I have hereunto set my hand.

RUDOLPH HOFFMAN. 

